REN and chronic kidney disease: In subgroups analyses, the association between the patients with poor post-AKD kidney function (post-AKD CKD stages 3-5) and a higher risk of death than those without CKD after AKD (post-AKD CKD stages 0-2) remained consistent across age, sex, diabetes, hypertension, congestive heart failure, cerebrovascular disease, and use of renin-angiotensin-aldosterone system inhibitors.